1 files changed, 336 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/arch/i386/image/eltorito.c b/contrib/syslinux-4.02/gpxe/src/arch/i386/image/eltorito.c
new file mode 100644
index 0000000..53eb2c0
--- /dev/null
+++ b/contrib/syslinux-4.02/gpxe/src/arch/i386/image/eltorito.c
@@ -0,0 +1,336 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * @file
+ *
+ * El Torito bootable ISO image format
+ *
+ */
+
+#include <stdint.h>
+#include <errno.h>
+#include <assert.h>
+#include <realmode.h>
+#include <bootsector.h>
+#include <int13.h>
+#include <gpxe/uaccess.h>
+#include <gpxe/image.h>
+#include <gpxe/segment.h>
+#include <gpxe/ramdisk.h>
+#include <gpxe/init.h>
+
+#define ISO9660_BLKSIZE 2048
+#define ELTORITO_VOL_DESC_OFFSET ( 17 * ISO9660_BLKSIZE )
+
+/** An El Torito Boot Record Volume Descriptor */
+struct eltorito_vol_desc {
+	/** Boot record indicator; must be 0 */
+	uint8_t record_indicator;
+	/** ISO-9660 identifier; must be "CD001" */
+	uint8_t iso9660_id[5];
+	/** Version, must be 1 */
+	uint8_t version;
+	/** Boot system indicator; must be "EL TORITO SPECIFICATION" */
+	uint8_t system_indicator[32];
+	/** Unused */
+	uint8_t unused[32];
+	/** Boot catalog sector */
+	uint32_t sector;
+} __attribute__ (( packed ));
+
+/** An El Torito Boot Catalog Validation Entry */
+struct eltorito_validation_entry {
+	/** Header ID; must be 1 */
+	uint8_t header_id;
+	/** Platform ID
+	 *
+	 * 0 = 80x86
+	 * 1 = PowerPC
+	 * 2 = Mac
+	 */
+	uint8_t platform_id;
+	/** Reserved */
+	uint16_t reserved;
+	/** ID string */
+	uint8_t id_string[24];
+	/** Checksum word */
+	uint16_t checksum;
+	/** Signature; must be 0xaa55 */
+	uint16_t signature;
+} __attribute__ (( packed ));
+
+/** A bootable entry in the El Torito Boot Catalog */
+struct eltorito_boot_entry {
+	/** Boot indicator
+	 *
+	 * Must be @c ELTORITO_BOOTABLE for a bootable ISO image
+	 */
+	uint8_t indicator;
+	/** Media type
+	 *
+	 */
+	uint8_t media_type;
+	/** Load segment */
+	uint16_t load_segment;
+	/** System type */
+	uint8_t filesystem;
+	/** Unused */
+	uint8_t reserved_a;
+	/** Sector count */
+	uint16_t length;
+	/** Starting sector */
+	uint32_t start;
+	/** Unused */
+	uint8_t reserved_b[20];
+} __attribute__ (( packed ));
+
+/** Boot indicator for a bootable ISO image */
+#define ELTORITO_BOOTABLE 0x88
+
+/** El Torito media types */
+enum eltorito_media_type {
+	/** No emulation */
+	ELTORITO_NO_EMULATION = 0,
+};
+
+struct image_type eltorito_image_type __image_type ( PROBE_NORMAL );
+
+/**
+ * Calculate 16-bit word checksum
+ *
+ * @v data		Data to checksum
+ * @v len		Length (in bytes, must be even)
+ * @ret sum		Checksum
+ */
+static unsigned int word_checksum ( void *data, size_t len ) {
+	uint16_t *words;
+	uint16_t sum = 0;
+
+	for ( words = data ; len ; words++, len -= 2 ) {
+		sum += *words;
+	}
+	return sum;
+}
+
+/**
+ * Execute El Torito image
+ *
+ * @v image		El Torito image
+ * @ret rc		Return status code
+ */
+static int eltorito_exec ( struct image *image ) {
+	struct ramdisk ramdisk;
+	struct int13_drive int13_drive;
+	unsigned int load_segment = image->priv.ul;
+	unsigned int load_offset = ( load_segment ? 0 : 0x7c00 );
+	int rc;
+
+	memset ( &ramdisk, 0, sizeof ( ramdisk ) );
+	init_ramdisk ( &ramdisk, image->data, image->len, ISO9660_BLKSIZE );
+	
+	memset ( &int13_drive, 0, sizeof ( int13_drive ) );
+	int13_drive.blockdev = &ramdisk.blockdev;
+	register_int13_drive ( &int13_drive );
+
+	if ( ( rc = call_bootsector ( load_segment, load_offset, 
+				      int13_drive.drive ) ) != 0 ) {
+		DBGC ( image, "ElTorito %p boot failed: %s\n",
+		       image, strerror ( rc ) );
+		goto err;
+	}
+	
+	rc = -ECANCELED; /* -EIMPOSSIBLE */
+ err:
+	unregister_int13_drive ( &int13_drive );
+	return rc;
+}
+
+/**
+ * Read and verify El Torito Boot Record Volume Descriptor
+ *
+ * @v image		El Torito file
+ * @ret catalog_offset	Offset of Boot Catalog
+ * @ret rc		Return status code
+ */
+static int eltorito_read_voldesc ( struct image *image,
+				   unsigned long *catalog_offset ) {
+	static const struct eltorito_vol_desc vol_desc_signature = {
+		.record_indicator = 0,
+		.iso9660_id = "CD001",
+		.version = 1,
+		.system_indicator = "EL TORITO SPECIFICATION",
+	};
+	struct eltorito_vol_desc vol_desc;
+
+	/* Sanity check */
+	if ( image->len < ( ELTORITO_VOL_DESC_OFFSET + ISO9660_BLKSIZE ) ) {
+		DBGC ( image, "ElTorito %p too short\n", image );
+		return -ENOEXEC;
+	}
+
+	/* Read and verify Boot Record Volume Descriptor */
+	copy_from_user ( &vol_desc, image->data, ELTORITO_VOL_DESC_OFFSET,
+			 sizeof ( vol_desc ) );
+	if ( memcmp ( &vol_desc, &vol_desc_signature,
+		      offsetof ( typeof ( vol_desc ), sector ) ) != 0 ) {
+		DBGC ( image, "ElTorito %p invalid Boot Record Volume "
+		       "Descriptor\n", image );
+		return -ENOEXEC;
+	}
+	*catalog_offset = ( vol_desc.sector * ISO9660_BLKSIZE );
+
+	DBGC ( image, "ElTorito %p boot catalog at offset %#lx\n",
+	       image, *catalog_offset );
+
+	return 0;
+}
+
+/**
+ * Read and verify El Torito Boot Catalog
+ *
+ * @v image		El Torito file
+ * @v catalog_offset	Offset of Boot Catalog
+ * @ret boot_entry	El Torito boot entry
+ * @ret rc		Return status code
+ */
+static int eltorito_read_catalog ( struct image *image,
+				   unsigned long catalog_offset,
+				   struct eltorito_boot_entry *boot_entry ) {
+	struct eltorito_validation_entry validation_entry;
+
+	/* Sanity check */
+	if ( image->len < ( catalog_offset + ISO9660_BLKSIZE ) ) {
+		DBGC ( image, "ElTorito %p bad boot catalog offset %#lx\n",
+		       image, catalog_offset );
+		return -ENOEXEC;
+	}
+
+	/* Read and verify the Validation Entry of the Boot Catalog */
+	copy_from_user ( &validation_entry, image->data, catalog_offset,
+			 sizeof ( validation_entry ) );
+	if ( word_checksum ( &validation_entry,
+			     sizeof ( validation_entry ) ) != 0 ) {
+		DBGC ( image, "ElTorito %p bad Validation Entry checksum\n",
+		       image );
+		return -ENOEXEC;
+	}
+
+	/* Read and verify the Initial/Default entry */
+	copy_from_user ( boot_entry, image->data,
+			 ( catalog_offset + sizeof ( validation_entry ) ),
+			 sizeof ( *boot_entry ) );
+	if ( boot_entry->indicator != ELTORITO_BOOTABLE ) {
+		DBGC ( image, "ElTorito %p not bootable\n", image );
+		return -ENOEXEC;
+	}
+	if ( boot_entry->media_type != ELTORITO_NO_EMULATION ) {
+		DBGC ( image, "ElTorito %p cannot support media type %d\n",
+		       image, boot_entry->media_type );
+		return -ENOTSUP;
+	}
+
+	DBGC ( image, "ElTorito %p media type %d segment %04x\n",
+	       image, boot_entry->media_type, boot_entry->load_segment );
+
+	return 0;
+}
+
+/**
+ * Load El Torito virtual disk image into memory
+ *
+ * @v image		El Torito file
+ * @v boot_entry	El Torito boot entry
+ * @ret rc		Return status code
+ */
+static int eltorito_load_disk ( struct image *image,
+				struct eltorito_boot_entry *boot_entry ) {
+	unsigned long start = ( boot_entry->start * ISO9660_BLKSIZE );
+	unsigned long length = ( boot_entry->length * ISO9660_BLKSIZE );
+	unsigned int load_segment;
+	userptr_t buffer;
+	int rc;
+
+	/* Sanity check */
+	if ( image->len < ( start + length ) ) {
+		DBGC ( image, "ElTorito %p virtual disk lies outside image\n",
+		       image );
+		return -ENOEXEC;
+	}
+	DBGC ( image, "ElTorito %p virtual disk at %#lx+%#lx\n",
+	       image, start, length );
+
+	/* Calculate load address */
+	load_segment = boot_entry->load_segment;
+	buffer = real_to_user ( load_segment, ( load_segment ? 0 : 0x7c00 ) );
+
+	/* Verify and prepare segment */
+	if ( ( rc = prep_segment ( buffer, length, length ) ) != 0 ) {
+		DBGC ( image, "ElTorito %p could not prepare segment: %s\n",
+		       image, strerror ( rc ) );
+		return rc;
+	}
+
+	/* Copy image to segment */
+	memcpy_user ( buffer, 0, image->data, start, length );
+
+	return 0;
+}
+
+/**
+ * Load El Torito image into memory
+ *
+ * @v image		El Torito file
+ * @ret rc		Return status code
+ */
+static int eltorito_load ( struct image *image ) {
+	struct eltorito_boot_entry boot_entry;
+	unsigned long bootcat_offset;
+	int rc;
+
+	/* Read Boot Record Volume Descriptor, if present */
+	if ( ( rc = eltorito_read_voldesc ( image, &bootcat_offset ) ) != 0 )
+		return rc;
+
+	/* This is an El Torito image, valid or otherwise */
+	if ( ! image->type )
+		image->type = &eltorito_image_type;
+
+	/* Read Boot Catalog */
+	if ( ( rc = eltorito_read_catalog ( image, bootcat_offset,
+					    &boot_entry ) ) != 0 )
+		return rc;
+
+	/* Load Virtual Disk image */
+	if ( ( rc = eltorito_load_disk ( image, &boot_entry ) ) != 0 )
+		return rc;
+
+	/* Record load segment in image private data field */
+	image->priv.ul = boot_entry.load_segment;
+
+	return 0;
+}
+
+/** El Torito image type */
+struct image_type eltorito_image_type __image_type ( PROBE_NORMAL ) = {
+	.name = "El Torito",
+	.load = eltorito_load,
+	.exec = eltorito_exec,
+};